Lacrosse is the fastest growing team sport in the country, increasing in popularity especially among girls, yet many are wondering why girls don't wear helmets for a game that has also seen a large increase in concussions.

As the science about concussions keeps getting better, doctors said the goal is to change the culture about concussions, from Pop Warner leagues to professional players.

Union Memorial Hospital's director of sports medicine, Dr. Andrew Tucker, said he has seen the aftermath of some big hits in his career. As the head physician for the Ravens, he said new guidelines from the American Academy of Neurology are spot-on for how players and coaches of all levels should handle concussions.

"We're trying to change the culture because the athlete's mindset is to play through things," Tucker said.

The academy has updated its guidelines from the mid-1990s. They were published Monday in the journal "Neurology" and say that any athlete suspected of experiencing a concussion should be immediately taken out of the game and shouldn't return until a doctor clears them.

Tucker said the key word is "suspected," which means there is still an element of a judgment call by the player or coach.

"If he's not exhibiting any of the signs or symptoms and acting normally and has no complaints, I think they can continue to participate and be observed. But some concussion symptoms don't appear immediately," Tucker warned.

The best-known symptoms of concussions include headache, sensitivity to light and sound, a loss of consciousness and changes to reaction time, balance, coordination, memory and speech.

The academy developed an app, which is available on iTunes or Google Play, to help coaches and parents quickly evaluate if a player is concussed or needs immediate care. Tucker said everyone needs to be more aware.

"It's a paradigm shift for all of us -- those of us who grew up when concussions were not really treated very seriously," he said.

Research developed for the new guidelines also revealed that the sports with the greatest risk for concussions are football, rugby, hockey and soccer. They now also include a separate category for girls' sports, where soccer and basketball topped the list.

The updated guidelines also put new focus on treating each individual case instead of using a grading system that used arbitrary timelines for a return to competition.